1. Field of the Invention
This application is directed to an apparatus that attaches to the end of an electrical fish tape to eliminate or reduce drag and friction while the fish tape is pushed through bends in electrical tubing.
2. Background and Prior Art
This invention relates generally to the field of electrical wiring installation and more specifically to an apparatus that attaches to the end of an electrical fish tape to eliminate our reduce drag and friction while the fish tape is pushed through bends in electrical tubing.
When installing electrical wire in conduit tubing, two things limit the distance between pull points in the tubing in an exposed industrial piping application. One is the length of the fish tape or snake. If the fish tape measures 200 feet, the pull points will be placed less than 200 feet part. For example, pull points could be placed at 180 feet intervals to ensure that the fish tape exposed sufficiently for manipulation at each end. The second aspect is the degree of bend between pull points. For example, a total of 360 degrees of bend is the extreme maximum bend between pull points. Typically installers will only put 270 degrees between pull points. If the bend is required to exceed 270 degrees, a junction box or condulet is installed as a pull point at every 270 degree interval. These junction boxes and condulets, which are used for pull points, drive up the cost of electrical installation, not only for the price of materials, which can be expensive, but the time for the initial wire pull and future pulls in the wire way because both points have to be manned to pull wire, which affects the cost of labor. It is difficult to push a fish tape through 360 degrees. After 270 degrees of bend is achieved, A-90 allows the end of the fish tape to roll through another bend with minimum resistance from friction/drag.
The most widely known method of getting a pull lead inside an electrical conduit at present is the fish tape itself. The fish tape is bent on the lead end in such a manner as to make the tip rounded. Many commercial fish tapes today have factory ends that accomplish the same end. Some fish tapes have a flexible metallic leader approximately 18″ long, but this leader is still subject to the same friction and drag inside the pipe and is not a solution to the underlying problem.
Numerous attempts to address the aforementioned problem have been patented. U.S. Pat. No. 4,171,123 to Woelkers is directed to a fish-shaped hanger for attaching multiple wire separately to a fish tape.
U.S. Pat. No. 4,596,381 to Hamrick utilizes a bag as the head of a fish tape and uses pressure differences between entry point and destination to urge the tape onward.
U.S. Pat. No. 4,895,221 to Carlson employs a sponge or foam material as a carrier for a lubricant near the head of the fish tape to decrease drag at bends.
U.S. Pat. No. 5,505,432 to Noonan discloses a fish tape head including an anti-snagging device in the form of a roller means disposal between the arms of a yoke.
The art continues to lack a low friction fish tape head which easily pushes through multiple conduit angles regardless of the orientation of the flat tape to the direction of the turn.